The present invention relates to a stair device for use in egress from and/or ingress to aquatic environments, such as on boats or at marinas. The stair device of the present invention is easily deployable and storable and may be stored in situ. More particularly, the present invention relates to a stair device which attaches to the hull, transom or swim platform of a boat or to a dock, deploys into the water and stores above the water line. In particular, the stair device of the present invention permits a person in the water to exit the water in an upright position, similar to the body position maintained while climbing stairs, and using primarily or solely the person's lower body strength and little or no upper body strength.
Several devices have been previously patented and/or marketed to assist people immersed in a body of water to exit the water and to climb onto a boat, other water vehicle or dock. For example, a common device used by boaters consists of a simple, flexible ladder comprised of two vertical rails made of a flexible materials, such as cotton or nylon rope and plastic or wood rungs suspended horizontally between such rails. Such ladders are inexpensive and easily deployed and do not require significant space for storage. Such ladders, however, are difficult to use as they require a person to possess sufficient upper body strength to initially pull themselves out of the water and up the ladder. Those without sufficient upper body strength or those carrying a load, such as scuba equipment, often find it impossible to independently exit the water using such ladders. Further complicating the use of such flexible ladders is their tendency to move while in use, thereby requiring additional strength and balance to exit the water.
A further disadvantage of prior art devices such as the flexible ladder is the difficulty of use with fins, waders or other footwear. Prior art devices in which the rungs or steps are bordered on one or both sides by a support or rail require an individual wearing aquatic footwear to carefully place their feet so that the footwear fits between the rails and through the rungs. Such careful maneuvering further complicates egress from the water. There is a need, therefore, for a stair device which may be easily used by an individual wearing footwear such as fins.
A number of ladder and/or platform devices have been previously patented and/or marketed to address the difficulty of climbing such a flexible ladder. For example, U.S. Pat. No. 4,768,618 (the '618 patent) provides a boat ladder device which provides fixed steps which do not move or swing while in use. The ladder of the '618 patent, however is quite bulky and must be disconnected from the boat transom for storage. Consequently, when not in use, the ladder of the '618 patent must occupy valuable and scarce storage space on the boat. U.S. Pat. No. 4,719,872 (the '872 patent) similarly describes a boat ladder which remains rigid while in use. However, the boat ladder of the '872 patent also requires that it be removed and stored when not in use. Other devices, such as that of U.S. Pat. No. 5,887,540 (the '540 patent), also provides easier access to a boat. However, because of the bulk and weight of the devices of the '618, '872 and '540 patents, such devices cannot be used in smaller watercraft, such as jet skis, dinghies, and compact power boats, which have recently become very popular. There is a need, therefore, for a stair device for use with watercraft which is sturdy but lighter in weight and which is not bulky so that it can remain in place at all times.
Because the prior art devices must be stored when not in use, these devices cannot be deployed by one already in the water. In an event of accidental disembarkation, one cannot use such prior art devices to re-embark on the boat. Therefore, there is a need for a boat stair device which would permit one to enter a boat from the water without prior intentional preparation and deployment of a stair device. Such an improvement would increase the safety of boating and other water sports activities utilizing watercraft.
The devices of each of the '618 and '872 patents provide a graduated vertical step permitting greater use of lower body strength and an easier climb than possible with a vertical ladder configuration. Nevertheless, because each of the ladders of the '618 and '872 patents must be stored when not in use, the size and number of steps which can be accommodated is limited. Therefore, the ladders of the '618 and '872 patents cannot be practically extended to extend significantly below the water line to a depth at which a person's feet may be easily positioned.
The American Boat and Yacht Council standard on boat ladders requires that boat ladder devices extend at least twelve inches below the waterline. The feet of a person in the water, however, generally rest at a depth substantially greater than the twelve inch standard. One using such prior art devices must generally hypercontract their leg, bringing their knee close in to their chest in to place a foot on the first rung of the device. Therefore, there is a need for a boat stair device which would permit an individual with limited flexibility and/or range of motion to simply step on a rung of the device at or near the position at which the individual's foot naturally rests in the water.